Retainer segment for a roller bearing for supporting a main shaft of a wind-power generator

ABSTRACT

A tapered roller bearing ( 31   a ) has a plurality of retainer segments ( 11   a,    11   d ) each having a pocket to house a tapered roller ( 34   a ), and arranged so as to be continuously lined with each other in a circumferential direction between an outer ring ( 32   a ) and an inner ring ( 33   a ). The retainer segment ( 11   a,    11   d ) is formed of a resin containing a filler material to lower a thermal linear expansion coefficient. In addition, a clearance ( 39   a ) is provided between the first retainer segment ( 11   a ) and the last retainer segment ( 11   d ) after the plurality of retainer segments ( 11   a,    11   d ) have been arranged in the circumferential direction without providing any clearance. Here a circumferential range (R) of the clearance ( 39   a ) is larger than 0.075% of a circumference of a circle passing through a center of the retainer segment ( 11   a,    11   d ) and smaller than 0.12% thereof at room temperature.

This application is a Divisional of U.S. Ser. No. 12/310,798 filed onMar. 6, 2009, which is a national phase of PCT/JP2007/067199 filed onSep. 4, 2007.

TECHNICAL FIELD

The present invention relates to a roller bearing, a retainer segment ofa roller bearing for supporting a main shaft of a wind-power generator,and a main shaft support structure of the wind-power generator and moreparticularly, to a retainer segment arranged in a circumferentialdirection to form one retainer of a roller bearing for supporting a mainshaft of a wind-power generator, and a roller bearing and a main shaftsupport structure containing the retainer segment of the roller bearingfor supporting the main shaft of the wind-power generator.

BACKGROUND ART

A roller bearing is composed of an outer ring, an inner ring, aplurality of rollers arranged between the outer ring and the inner ring,and a retainer retaining the plurality of rollers in general. Theretainer is composed of one integrated, that is, annular component ingeneral.

Since a roller bearing to support a main shaft of a wind-power generatorprovided with a blade for receiving wind has to receive a high load, theroller bearing itself is large in size. Thus, since the components suchas a roller and a retainer that compose the roller bearing are large insize also, it is difficult to produce and assemble the components. Inthis case, when each component can be split, the production andassembling become easy.

Here, a technique concerned with a split type retainer split by a splitline extending along a rotation axis of a bearing, in a roller bearingis disclosed in European Patent Publication No. 1408248A2. FIG. 39 is aperspective view showing a retainer segment of the split type retainerdisclosed in the European Patent Publication No. 1408248A2. Referring toFIG. 39, a retainer segment 101 a includes a plurality of column parts103 a, 103 b, 103 c, 103 d, and 103 e extending along a rotation axis ofa bearing so as to form a plurality pockets 104 to house rollers, andconnection parts 102 a and 102 b extending in a circumferentialdirection so as to connect the plurality of column parts 103 a to 103 e.

FIG. 40 is a sectional view showing a part of a tapered roller bearingcontaining the retainer segment 101 a shown in FIG. 39. Referring toFIGS. 39 and 40, a constitution of a tapered roller bearing 111containing the retainer segment 101 a will be described. The taperedroller bearing 111 includes an outer ring 112, an inner ring 113, aplurality of tapered rollers 114, and a plurality of retainer segments101 a, 101 b, and 101 c retaining the plurality of tapered rollers 114.The plurality of tapered rollers 114 are retained by the plurality ofretainer segments 101 a and the like in the vicinity of a PCD (PitchCircle Diameter) 105 in which the behavior of the roller is most stable.The retainer segment 101 a retaining the plurality of tapered rollers114 is connected such that the column parts 103 a and 103 e positionedoutermost in the circumferential direction abut on the circumferentiallyadjacent retainer segments 101 b and 101 c having the sameconfiguration. The plurality of retainer segments 101 a, 101 b, and 101c are continuously lined with each other and assembled in the taperedroller bearing 111, whereby one annular retainer is formed in thetapered roller bearing 111.

According to the European Patent Publication No. 1408248A2, after theretainer segments formed of a resin have been arranged so as to becontinuously lined with each other, a circumferential range of a lastclearance generated between the first retainer segment and the lastretainer segment is to be not less than 0.15% of a circumference of acircle passing through the center of the retainer segment but less than1% thereof. In this constitution, a collision noise due to collision ofthe retainer segments is prevented, and the retainer segments areprevented from being stuck due to thermal expansion. In addition,according to the European Patent Publication No. 1408248A2, the retainersegment is formed of polyphenyl sulfide (referred to as “PPS”hereinafter), or polyether ether ketone (referred to as “PEEK”hereinafter).

Here, even when the circumferential range of the clearance is set withinthe above range, the following problem on which the inventor focused isnot solved. FIG. 41 is a schematic sectional view showing a part of thetapered roller bearing 111 when the tapered roller bearing 111 is usedas the bearing to support the main shaft of the wind-power generator. Inaddition, a clearance 115 generated between the retainer segments 101 aand 101 c is shown with exaggeration in order to be easily understood.

Referring to FIG. 41, a main shaft 110 of the wind-power generatorsupported by the tapered roller bearing 111 is used as a horizontalshaft. When the tapered roller bearing 111 is used, the retainersegments 101 a to 101 c revolve in a direction shown by arrows in FIG.41. The retainer segments 101 a to 101 c revolve such that the retainersegments 101 a to 101 c push the adjacent retainer segments 101 a to 101c continuously in the direction of the arrows. In this case, the taperedroller and the retainer segment 101 a free-fall at a position shown byXXXXI in FIG. 41. In this case, since the retainer segments 101 a and101 c collide with each other, the retainer segments 101 a and 101 c aredeformed, and end faces thereof abrade away, and a collision noise isgenerated, which could considerably lower the function of the taperedroller bearing 111.

When the tapered roller bearing 111 is used as the bearing to supportthe main shaft 110 of the wind-power generator, since the retainersegments 101 a to 101 c are large in size, the problem due to thecollision at the time of free-falling is serious. Therefore, theabove-described range of the clearance is not preferable and thecircumferential clearance needs to be smaller. However, there is a limitof reducing the circumferential range of the clearance in the case ofthe retainer segment formed of the resin due to thermal expansion.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a roller bearingcapable of preventing its function from being lowered.

It is another object of the present invention to provide a rollerbearing capable of preventing a retainer segment from being damaged andenabling a roller to roll smoothly.

It is still another object of the present invention to provide aretainer segment of a roller bearing for supporting a main shaft of awind-power generator capable of preventing a function of the bearingfrom being lowered.

It is still another object of the present invention to provide aretainer segment of a roller bearing for supporting a main shaft of awind-power generator capable of preventing the retainer segment frombeing damaged and enabling a roller to roll smoothly.

It is still another object of the present invention to provide a mainshaft support structure of a wind-power generator capable of preventingits function from being lowered.

It is still another object of the present invention to provide along-lived main shaft support structure of a wind-power generator.

A roller bearing according to the present invention includes an outerring, an inner ring, a plurality of rollers arranged between the outerring and the inner ring, and a plurality of retainer segments eachhaving a pocket to house the roller, and arranged to be continuouslylined with each other in a circumferential direction between the outerring and the inner ring. The retainer segment is formed of a resincontaining a filler material to lower a thermal linear expansioncoefficient. In addition, a clearance is provided between the firstretainer segment and the last retainer segment after the plurality ofretainer segments have been arranged in the circumferential directionwithout providing any clearance. Here, a circumferential range of theclearance is larger than 0.075% of a circumference of a circle passingthrough a center of the retainer segment and smaller than 0.12% thereof,at room temperature.

Thus, since the retainer segment is formed of the resin containing thefiller material to lower the thermal linear expansion coefficient, thedimensional change of the retainer segment due to the thermal expansioncan be reduced. Thus, the circumferential clearance generated betweenthe retainer segments can be smaller than the range disclosed in theEuropean Patent Publication No. 1408248A2.

Here, the bearing components such as the outer ring, the inner ring, andthe tapered roller in the tapered roller bearing are made of steel suchas case-hardening steel in general. Thus, the bearing component such asthe outer ring also thermally expands due to a temperature change. Here,when the thermal linear expansion coefficient of the retainer segmentand the thermal linear expansion coefficient of the bearing componentare taken into account, the circumferential range of the clearance atroom temperature can be reduced to 0.075% of the circumference of thecircle passing through the center of the retainer segment in practicalusage. Consequently, since the circumferential clearance is larger than0.075% of the circumference, the circumferential range of the clearanceis prevented from becoming negative and the retainer segments areprevented from being pressed and stuck.

In addition, it is preferable that a safe ratio of the retainer composedof the plurality of retainer segments is high in the tapered rollerbearing used in the above usage in view of durability and reliabilityimprovement. The safe ratio of the retainer becomes high as thecircumferential range of the clearance is decreased. The safe ratio ofthe retainer is required to be 4.0 or more in view of fatigue strengthof the material of the retainer segment and a stress generated in theretainer segment. Here, when the circumferential range of the clearanceat room temperature is smaller than 0.12% of the circumference of thecircle passing through the center of the retainer segment, the saferatio can be surely 4.0 or more. Thus, the defect in strength due to thecollision between the retainer segments, including the above problem,can be prevented.

When the retainer segment is formed of the resin containing the fillermaterial to lower the thermal linear expansion coefficient, and thecircumferential clearance between the retainer segments is within theabove range, the defect in strength due to the collision between theretainer segments and the deformation due to circumferential pressingbetween the retainer segments can be prevented. Therefore, the functionof the bearing having the above retainer segment can be prevented frombeing lowered.

Here, the retainer segment is a unit body split by the split lineextending along the rotation axis of the bearing so as to have at leastone pocket to house the roller in one annular retainer. In addition, thefirst retainer segment designates the retainer segment arranged firstwhen the retainer segments are arranged so as to be continuously linedwith each other in the circumferential direction, and the last retainersegment designates the retainer segment arranged last when the retainersegments are arranged so as to be continuously lined with each other inthe circumferential direction such that the adjacent retainer segmentsabut on each other. The plurality of retainer segments are arranged soas to be continuously lined with each other in the circumferentialdirection and assembled in the roller bearing, whereby the one annularretainer is constituted.

Preferably, the filler material contains carbon fiber and/or glassfiber. Since the filler material is in the form of fiber, the thermallinear expansion coefficient, that is, thermal expansion coefficient canbe effectively lowered.

Further preferably, the resin is PEEK. According to PEEK, its thermalexpansion coefficient is lower than other resins and the filler materialcan be easily contained to lower the thermal expansion coefficient.

Further preferably, the thermal linear expansion coefficient of theresin is 1.3×10⁻⁵/C.° to 1.7×10⁻⁵/C.°. The member such as the outer ringthat composes the bearing is formed of steel such as case-hardeningsteel in general. The thermal linear expansion coefficient of such steelis about 1.12×10⁻⁵/C.°. Therefore, when the thermal linear expansioncoefficient of the resin is within the above range, the difference inthermal linear expansion coefficient from the bearing component such asthe outer ring is allowable in the practical usage. In addition, thethermal linear expansion coefficient of PEEK is about 4.7×10⁻⁵/C.°, andthe thermal linear expansion coefficient of PPS is about 5.0×10⁻⁵/C.°.

Further preferably, a filling rate of the filler material in the resinis 20% by weight to 40% by weight. When the filling rate of the fillermaterial in the resin is within the above range, the thermal expansioncoefficient of the resin can be greatly reduced without generating otherdefects due to the filler material.

Further preferably, the roller is a tapered roller. The roller bearingused in the main shaft of the wind-power generator has to receive highmoment load, thrust load, and radial load. Here, since the roller is thetapered roller, high moment load and the like can be received.

Further preferably, the retainer segment has a plurality of column partsextending along a rotation axis of the bearing so as to form pockets tohouse the rollers, and a connection part extending in thecircumferential direction so as to connect the plurality of columnparts. The retainer segment guides the rollers. One guide click having acontact part with the roller and a recess part formed on thecircumferential inner side of the contact part are provided at a sidewall surface of the column part.

The retainer segment disclosed in the European Patent Publication No.1408248A2 guides the track ring. Meanwhile, when the split type retainersegment guides the rollers, damage and collision noise can be reduced atthe time of contact with the track ring.

Here, the guide click that is in contact with the roller is provided atthe side wall surface of the column part so that the retainer segmentguides the rollers. FIG. 42 is a sectional view showing one part of aretainer segment provided with guide clicks, taken from the inside ofthe pocket. Referring to FIG. 42, a retainer segment 121 includes acolumn part 122 to form a pocket, and a pair of connection parts 123 aand 123 b to connect the column parts 122. Two guide clicks 124 a and124 b are provided at a side wall surface of the column part 122. Theguide clicks 124 a and 124 b are arranged so as to be spaced in a rollerlength direction. According to the above constitution, lubricant oil canpass through a clearance 125 provided between the guide clicks 124 a and124 b.

Meanwhile, since the plurality of retainer segments 121 are provided inthe roller bearing, it is necessary to produce the retainer segments inlarge volume. Therefore, it is preferable that the retainer segment 121is formed of a resin and produced by injection molding.

However, when the retainer segment 121 having the above configuration isproduced by injection molding, shrinkage is generated at the tip ends ofthe guide clicks 124 a and 124 b, and the centers of the guide clicks124 a and 124 b are recessed. This will be described with reference toFIG. 43. FIG. 43 is a view showing one part of the retainer segment 121in this case. In addition, FIG. 43 is a view showing the retainersegment in FIG. 42 taken from a direction shown by an arrow XXXXIII inFIG. 42.

Referring to FIGS. 42 and 43, center parts 127 a and 127 b of the guideclicks 124 a and 124 b of the retainer segment 121 in the roller lengthdirection are recessed due to shrinkage at the time of injectionmolding. Here, when a roller 131 starts to roll, edge parts 126 a, 126b, 126 c, and 126 d positioned at both ends in the roller lengthdirection are brought in contact with the roller 131. Accordingly, theedge parts 126 a to 126 d are worn and the postures of the roller 131and the retainer segment 121 cannot be stable. In addition, in the caseof the retainer segment 121 formed of the resin in which reinforcedfiber is filled, the reinforced fiber exposes on its surface due to theabrasion of the resin part, which could cause the roller 131 to be worn.According to the roller bearing having such retainer segment 121, theroller cannot roll smoothly. In addition, as shown in FIG. 44, the sameis true in the case where edge parts 126 e and 126 f in the guide clicks124 c and 124 d are in contact with the roller 131.

In addition, since the retainer segment 121 having the aboveconfiguration is provided with the plurality of guide clicks, a numberof edge parts 126 a to 126 d of the guide clicks 124 a and 124 b areprovided. In this case, the fluidity of the resin material deterioratesat the time of the injection molding, and an internal defect is likelyto be generated. In addition, like the retainer segment disclosed in theEuropean Patent Publication No. 1408248A2, when the retainer segment hasthe complicated configuration in which the guide click is provided onlyon the large diameter side, and a part of the column part projects in aradial direction, its configuration could be deformed and not have thedesigned range in addition to the problem due to the shrinkage andexpansion of the resin.

However, as described above, the retainer segment has the plurality ofcolumn parts extending in the direction along the rotation axis of thebearing so as to form the pockets to house the rollers, and theconnection parts extending in the circumferential direction so as toconnect the plurality of column parts, and the retainer segment guidesthe rollers, and the side wall surface of the column part is providedwith the one guide click having the contact part with the roller, andthe recess part is formed on the circumferential inner side of thecontact part. Thus, since the one guide click is provided at the sidewall surface of the column part in the retainer segment guiding therollers, the number of the edge parts of the guide click can be reduced.Thus, since the above retainer segment is simple in configuration, athickness difference is small, and the internal defect and thedeformation at the time of the injection molding can be prevented. Inaddition, the contact area between the tip end of the guide click andthe roller is increased and the surface pressure at the time of contactcan be lowered. Furthermore, the rigidity of the column part and thusthe retainer segment can be improved. According to the roller bearinghaving the above retainer segment, the postures of the roller and theretainer segment can be stable. In addition, since the recess part ispositioned on the circumferential inner side of the contact part, thelubricant oil can pool in the recess part. Thus, since the lubricant oilcan be supplied from the recess part to the contact part, thelubricating property is improved. Therefore, the retainer segment isprevented from being damaged and the roller can roll smoothly.

Preferably, the guide click is provided in the center of the side wallsurface of the column part in a roller length direction. Thus, since theroller in the pocket and the guide click are in contact with each otherin the center of roller length, the postures of the roller and theretainer segment can be stable. Therefore, the roller can roll moresmoothly.

Further preferably, a length of the guide click in the roller lengthdirection is roughly equal to an entire length of the pocket in theroller length direction. Thus, since the contact part of the roller andthe guide click can be increased, the postures of the roller and theretainer segment can be more stable. Therefore, the roller can roll moresmoothly. Here, it is to be noted that the term “roughly entire length”means at least 50% or more of the pocket length in the roller lengthdirection and preferably, 75% or more thereof.

Further preferably, the recess part is formed by shrinkage generatedwhen the retainer segment is molded. Since the recess part is continuedto the surface of the guide click smoothly, the lubricant oil can easilyflow in and flow out. In addition, since stress concentration is notlikely to be generated at the recess part having such configuration, thedamage can be reduced.

Further preferably, an angle at a corner part positioned at a tip end ofthe guide click is an obtuse angle in a section provided by cutting theretainer segment by a plane passing through the guide click and crossinga rotation axis of the bearing at right angles. Thus, the amount of thelubricant oil scraped off in the vicinity of the roller and the guideclick of the retainer segment by the corner part positioned at the tipend of the guide click can be reduced. Thus, since the lubricant oil inthe vicinity of the roller and the guide click can be easily suppliedinto the pocket, the lubrication defect is prevented and the roller canroll smoothly.

Further preferably, the corner part is chamfered. Thus, the amount ofthe lubricant oil scraped off by the corner part can be more reduced.Therefore, the roller can roll more smoothly.

Further preferably, the chamfered part is a R-chamfered part. Thus,since the corner part can become a smooth surface, the amount of thelubricant oil scraped off by the corner part can be more reduced.Therefore, the roller can roll more smoothly.

According to another aspect of the present invention, a retainer segmentof a roller bearing for supporting a main shaft of a wind-powergenerator has a pocket to house a roller and it is arranged so as to becontinuously lined in a circumferential direction, and is formed of aresin containing a filler material to lower a thermal linear expansioncoefficient.

According to the retainer segment of the roller bearing for supportingthe main shaft of the wind-power generator, since a difference inthermal linear expansion coefficient from the bearing component such asthe outer ring composing the roller bearing for supporting the mainshaft of the wind-power generator can be small, a change of thecircumferential range of the clearance due to a temperature change canbe small. Thus, the circumferential clearance between the retainersegments can be small and kept within the above range. Therefore, thefunction of the roller bearing having the above retainer segment can beprevented from being lowered.

Preferably, the filler material contains carbon fiber and/or glassfiber. Thus, the thermal expansion coefficient can be effectivelylowered.

Further preferably, the resin is polyether ether ketone. Thus, thethermal expansion coefficient can be easily lowered with the fillermaterial contained.

Further preferably, the thermal linear expansion coefficient of theresin is 1.3×10⁻⁵/C.° to 1.7×10⁻⁵/C.°. Thus, the difference in thermallinear expansion coefficient from the bearing component such as theouter ring is allowable in the practical usage.

Further preferably, a filling rate of the filler material in the resinis 20% by weight to 40% by weight. Thus, the thermal linear expansioncoefficient of the resin can be greatly lowered without generating otherdefects due to the filler material.

Further preferably, the retainer segment of the roller bearing forsupporting the main shaft of the wind-power generator has a plurality ofcolumn parts extending along a rotation axis of the bearing so as toform pockets to house rollers, and a connection part extending in thecircumferential direction so as to connect the plurality of columnparts, and the retainer segment guides the rollers. One guide clickhaving a contact part with the roller and a recess part formed on thecircumferential inner side of the contact part are provided at a sidewall surface of the column part.

According to the above retainer segment of the roller bearing, sinceonly one guide click is provided at the side wall surface of the columnpart, the number of edge parts of the guide click can be reduced. Sincethe retainer segment has the above simple configuration, a thicknessdifference is small and an internal defect and deformation can beprevented from being generated at the time of injection molding. Inaddition, a contact area between the tip end of the guide click and theroller can be increased and a surface pressure at the time of contactcan be lowered. Furthermore, the rigidity of the column part and thusthe retainer segment can be improved. According to the roller bearinghaving the above retainer segment, the postures of the roller and theretainer segment can be stable. In addition, since the recess part ispositioned on the circumferential inner side of the contact part, thelubricant oil can pool in the recess part. Thus, the lubricant oil canbe supplied from the recess part to the contact part, the lubricatingproperty is improved. Therefore, the retainer segment is prevented frombeing damaged and the roller can roll smoothly.

Preferably, the recess part is formed by shrinkage generated when theretainer segment is molded. Since the recess part is continued to thesurface of the guide click smoothly, the lubricant oil can easily flowin and flow out. In addition, since stress concentration is not likelyto be generated at the recess part having the above configuration, thedamage can be reduced.

According to still another aspect of the present invention, a main shaftsupport structure of a wind-power generator includes a blade receivingwind power, a main shaft having one end fixed to the blade and rotatingtogether with the blade, and a roller bearing assembled in a fix memberto support the main shaft rotatably. The roller bearing has an outerring, an inner ring, a plurality of rollers arranged between the outerring and the inner ring, and a plurality of retainer segments eachhaving a pocket to house the roller, and arranged so as to becontinuously lined with each other in a circumferential directionbetween the outer ring and the inner ring. The retainer segment isformed of a resin containing a filler material to lower a thermal linearexpansion coefficient. A clearance is provided between the firstretainer segment and the last retainer segment after the plurality ofretainer segments have been arranged in the circumferential directionwithout providing any clearance. A circumferential range of theclearance is larger than 0.075% of a circumference of a circle passingthrough a center of the retainer segment and smaller than 0.12% thereofat room temperature.

Since the main shaft support structure of the wind-power generatorincludes the roller bearing in which the function of the bearing isprevented from being lowered, the function of the main support structureof the wind-power generator itself can be prevented from being lowered.

Preferably, the retainer segment has a plurality of column partsextending along a rotation axis of the bearing so as to form pockets tohouse the rollers, and a connection part extending in thecircumferential direction so as to connect the plurality of columnparts, and the retainer segment guides the rollers, and one guide clickhaving a contact part with the roller and a recess part formed on thecircumferential inner side of the contact part are provided at a sidewall surface of the column part.

Since the main shaft support structure of the wind-power generatorincludes the roller bearing in which the retainer segment is preventedfrom being damaged and the roller can roll smoothly, it has a long life.

According to the present invention, since the retainer segment is formedof the resin containing the filler material to lower the thermal linearexpansion coefficient, and the circumferential clearance between theretainer segments is set within the above-described range, the defect instrength due to the collision of the retainer segments and thedeformation due to the circumferential pressing between the retainersegments can be prevented. Therefore, the function of the roller bearingincluding such retainer segment can be prevented from being lowered.

In addition, according to the retainer segment of the roller bearing forsupporting the main shaft of the wind-power generator, since thedifference in thermal linear expansion coefficient from the bearingcomponent such as the outer ring that composes the roller bearing forsupporting the main shaft of the wind-power generator can be small, thechange of the circumferential range of the clearance due to thetemperature change can be small. Thus, the circumferential clearancebetween the retainer segments can be small and kept within the setrange. Therefore, the function of the roller bearing including suchretainer segment can be prevented from being lowered.

In addition, since the main shaft support structure of the wind-powergenerator includes the roller bearing in which the function is preventedfrom being lowered, the function of the main support structure of thewind-power generator itself can be prevented from being lowered.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an enlarged sectional view showing a clearance between a firstretainer segment and a last retainer segment in a tapered roller bearingaccording to one embodiment of the present invention;

FIG. 2 is a perspective view showing the retainer segment contained inthe tapered roller bearing according to the one embodiment of thepresent invention;

FIG. 3 is a sectional view showing the retainer segment in FIG. 2 cut bya plane passing through a line III-III in FIG. 2 and crossing a rotationaxis of the bearing at right angles;

FIG. 4 is a sectional view showing the retainer segment in FIG. 2 cut bya plane passing through the center of a column part and crossing acircumferential direction at right angles;

FIG. 5 is a schematic sectional view showing the tapered roller bearingin which the plurality of retainer segments are arranged in thecircumferential direction;

FIG. 6 is an enlarged sectional view showing adjacent retainer segments;

FIG. 7 is a graph showing a relation between a safe ratio of a retainerand a circumferential range of a clearance;

FIG. 8 is a view showing one example of a main shaft support structureof a wind-power generator including the tapered roller bearing accordingto the present invention;

FIG. 9 is a schematic side view showing the main shaft support structureof the wind-power generator shown in FIG. 8;

FIG. 10 is a perspective view showing a retainer segment in a taperedroller bearing according to another embodiment of the present invention;

FIG. 11 is a sectional view showing a part of the retainer segmentcontained in the tapered roller bearing according to another embodimentof the present invention taken from the inner side of a pocket;

FIG. 12 is a sectional view showing the retainer segment shown in FIG.10 cut by a plane passing through a line XI-XI in FIG. 10 and crossing ashaft at right angles;

FIG. 13 is a sectional view showing the retainer segment shown in FIG.10 cut by a plane passing through the center of a column part andcrossing a circumferential direction at right angles;

FIG. 14 is an enlarged sectional view showing a pocket part of theretainer segment shown in FIG. 12;

FIG. 15 is an enlarged sectional view showing a corner part of a guideclick provided in the retainer segment;

FIG. 16 is a schematic sectional view showing a tapered roller bearingin which the plurality of retainer segments are arranged in thecircumferential direction;

FIG. 17 is an enlarged sectional view showing the adjacent retainersegments;

FIG. 18 is an enlarged sectional view showing a corner part of a guideclick provided in the retainer segment according to another embodimentof the present invention;

FIG. 19 is a sectional view showing a double-row tapered roller bearingaccording to still another embodiment of the present invention;

FIG. 20 is an enlarged view showing one part of the double-row taperedroller bearing shown in FIG. 19;

FIG. 21 is a flowchart roughly showing a method for assembling thedouble-row tapered roller bearing shown in FIG. 19;

FIG. 22 is a sectional view showing a state in which one inner ring isassembled in a rotation shaft;

FIG. 23 is a sectional view showing a state in which one tapered rollerand one retainer segment are arranged;

FIG. 24 is a sectional view showing a state in which an inner ringintermediate element is arranged;

FIG. 25 is sectional view showing a state in which an outer ring isarranged;

FIG. 26 is a sectional view showing a state in which the other taperedroller and the other retainer segment are arranged;

FIG. 27 is an enlarged sectional view showing one part of an inner ringcontained in the double-row tapered roller bearing according to anotherembodiment of the present invention;

FIG. 28 is an enlarged sectional view showing one part of an inner ringcontained in the double-row tapered roller bearing according to stillanother embodiment of the present invention;

FIG. 29 is a view showing a tapered roller bearing supporting the mainshaft of the wind-power generator;

FIG. 30 is an enlarged view showing the tapered roller shown in FIG. 29;

FIG. 31 is a view showing a state before one inner ring member of thetapered roller is assembled in a main shaft;

FIG. 32 is a view showing a state after a tapered roller bearing hasbeen assembled in the main shaft;

FIG. 33 is a flowchart showing a main method for assembling the oneinner ring member of the tapered roller bearing in the main shaft;

FIG. 34 is a view showing a tapered roller bearing supporting the mainshaft of the wind-power generator;

FIG. 35 is an enlarged view showing the tapered roller shown in FIG. 34;

FIG. 36 is a view showing a state before the one inner ring member ofthe tapered roller bearing is assembled in the main shaft;

FIG. 37 is a view showing a state after the tapered roller bearing hasbeen assembled in the main shaft;

FIG. 38 is a flowchart showing a main method for assembling the oneinner ring member of the tapered roller bearing in the main shaft;

FIG. 39 is a perspective view showing a conventional retainer segment;

FIG. 40 is a sectional view showing a part of a tapered roller bearingincluding the retainer segment shown in FIG. 39 cut by a plane crossinga rolling axis of the bearing at right angles;

FIG. 41 is a schematic sectional view showing the tapered roller bearingincluding the retainer segment shown in FIG. 40 cut by a plane crossingthe rolling axis of the bearing at right angles;

FIG. 42 is a view showing one part of a retainer segment provided with asplit type guide click;

FIG. 43 is a view showing the retainer segment shown in FIG. 42 takenfrom a radial direction; and

FIG. 44 is a view showing the retainer segment taken from the radialdirection when one edge part of the guide click is in contact with aroller.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described with reference tothe drawing hereinafter. FIG. 2 is a perspective view showing a retainersegment 11 a provided in a tapered roller bearing according to oneembodiment of the present invention, to support a main shaft of awind-power generator. FIG. 3 is a sectional view showing the retainersegment 11 a shown in FIG. 2 cut by a plane containing a line III-III inFIG. 2 and crossing a rotation axis of the bearing at right angles. FIG.4 is a sectional view showing the retainer segment 11 a shown in FIG. 2cut by a plane passing through the center of a column part 14 a andcrossing a circumferential direction at right angles. In addition, aplurality of tapered rollers 12 a, 12 b, and 12 c retained by theretainer segment 11 a are shown by dotted lines in FIGS. 3 and 4 so asto be easily understood. In addition, a PCD 22 a is shown by a one-dotchain line.

First, a constitution of the retainer segment 11 a contained in thetapered roller bearing will be described with reference to FIGS. 2 to 4.The retainer segment 11 a is a segment of one annular retainer split bya split line extending along the rotation axis of the bearing so as tohave at least one pocket to contain the roller. The retainer segment 11a includes four column parts 14 a, 14 b, 14 c, and 14 d extending alongthe rotation axis of the bearing, and a pair of connection parts 15 aand 15 b positioned at axial both ends and extending in acircumferential direction so as to connect the four column parts 14 a to14 d so that pockets 13 a, 13 b, and 13 c to hold the tapered rollers 12a, 12 b, 12 c, and 12 d are formed. Here, according to the retainersegment 11 a, the column parts 14 a and 14 d are positioned at itscircumferential outer side ends.

The connection parts 15 a and 15 b have predetermined curvature radiusesin the circumferential direction so that the plurality of retainersegments 11 a are arranged so as to be continuously lined with eachother in the circumferential direction to form one annular retainer whenassembled in the tapered roller bearing. According to the connectionparts 15 a and 15 b, the curvature radius of the connection part 15 apositioned on a small diameter side of the tapered rollers 12 a to 12 cis smaller than the curvature radius of the connection part 15 bpositioned on a large diameter side of the tapered rollers 12 a to 12 c.

According to the column parts 14 a and 14 b positioned oncircumferential both sides of the pocket 13 a, and the column parts 14 cand 14 d positioned on circumferential both sides of the pocket 13 c,guide clicks 17 a, 17 b, 17 c, and 17 d are provided on the innerdiameter side of the side wall surface of the column parts 14 a to 14 dto regulate the movement of the retainer segment 11 a toward the radialouter side. The guide clicks 17 a to 17 d are in contact with thetapered rollers 12 a and 12 c held in the pockets 13 a and 13 c, on theinner diameter side. In addition, according to the column parts 14 b and14 c positioned on circumferential both sides of the pocket 13 b, guideclicks 18 b and 18 c are provided on the outer diameter side of the sidewall surfaces of the column parts 14 b and 14 c to regulate the movementof the retainer segment 11 a toward the radial inner side. The guideclicks 18 b and 18 c are in contact with the tapered roller 12 b held inthe pocket 13 b, on the outer diameter side. Each of the guide clicks 17a to 17 d, 18 b, and 18 c projects toward the pockets 13 a to 13 c. Inaddition, as shown in the section in FIG. 3, each guide surface of theguide clicks 17 a to 17 d, 18 b, and 18 c is arc-shaped in section tofollow each rolling surface of the tapered rollers 12 a to 12 c. Thus,since the guide clicks 17 a to 17 d, 18 b, and 18 c are provided on theinner diameter side and the outer diameter side, the rollers are incontact with the guide surfaces of the guide clicks 17 a to 17 d, 18 b,and 18 c and the retainer segment 11 a guides the rollers. In addition,end faces 21 a and 21 b provided on the circumferential outer sides ofthe column parts 14 a and 14 d positioned on the circumferential outersides are flat.

Here, the retainer segment 11 a is formed of a resin containing a fillermaterial to lower a thermal linear expansion coefficient. Thus, since adifference in thermal linear expansion coefficient from a bearingcomponent such as an outer ring in the roller bearing for supporting amain shaft of a wind-power generator can be small as will be describedbelow, a dimensional change of a circumferential clearance due to atemperature change can be small.

In addition, the resin is preferably PEEK. Since the thermal linearexpansion coefficient of PEEK itself is about 4.7×10⁻⁵/C.° C., and thethermal linear expansion coefficient is low as compared with other resinmaterials, the thermal linear expansion coefficient can be easilylowered by containing the filler material.

In addition, it is preferable that the filler material contains carbonfiber and/or glass fiber. Since such filler material is in a fibrousform, the thermal linear expansion coefficient, that is, a thermalexpansion coefficient can be lowered effectively.

In addition, it is preferable that the thermal linear expansioncoefficient of the resin is 1.3×10⁻⁵/° C. to 1.7×10⁻⁵/° C. The bearingcomponent such as the outer ring in the bearing is formed of steel suchas case hardening steel in general. The thermal linear expansioncoefficient of such steel is about 1.12×10⁻⁵/° C. Therefore, when thethermal linear expansion coefficient of the resin is within the aboverange, the difference in thermal linear expansion coefficient from thebearing component such as the outer ring is allowable in practicalusage.

In addition, it is preferable that a filling rate of the filler materialin the resin is 20% by weight to 40% by weight. Thus, the thermalexpansion coefficient of the resin can be considerably lowered withoutgenerating another trouble due to filling of the filler material, suchas strength poverty due to excessive filling amount.

In addition, since the plurality of retainer segments 11 a are providedin one tapered roller bearing, its productivity is required to beimproved. Thus, according to the above constitution, the retainersegment having the same configuration can be easily produced in largenumbers by injection molding and the like.

Here, more specifically, it is preferable that the retainer segment 11 acontains 30% by weight of carbon fiber as the filler material and isformed of PEEK having the linear expansion coefficient of 1.5×10⁻⁵/° C.The above retainer segment 11 a is considerably different from aretainer segment formed of PEEK having a thermal linear expansioncoefficient of 4.7×10⁻⁵/° C., and a retainer segment formed of PPShaving a thermal linear expansion coefficient of 5.0×10⁻⁵/° C.

Next, a description will be made of a constitution of the tapered rollerbearing containing the above retainer segment 11 a. FIG. 5 is aschematic sectional view showing a tapered roller bearing 31 a in whichthe plurality of retainer segments 11 a, 11 b, 11 c, and 11 d arearranged in the circumferential direction, taken from an axialdirection. In addition, FIG. 6 is an enlarged view showing a part VI inFIG. 5. Here, since the retainer segments 11 b, 11 c, and 11 d have thesame configuration and are formed of the same material as the retainersegment 11 a, their descriptions will be omitted. In addition, in FIG.5, the tapered roller retained in the retainer segment 11 a is omitted.In addition, it is to be noted that the retainer segment arranged firstis the retainer segment 11 a, and the retainer segment arranged last isthe retainer segment 11 d among the plurality of retainer segments 11 ato 11 d.

Referring to FIGS. 5 and 6, the tapered roller bearing 31 a includes anouter ring 32 a, an inner ring 33 a, a plurality of tapered rollers 34a, and the plurality of retainer segments 11 a to 11 d. The retainersegments 11 a to 11 d are arranged so as to be continuously lined witheach other in the circumferential direction with no clearance. Here, theretainer segment 11 a is arranged first, and then the retainer segment11 b is arranged such that the retainer segment 11 b abuts on theretainer segment 11 a, that is, such that the end face 21 a of theretainer segment 11 a abuts on an end face 21 c of the retainer segment11 b. Then, the retainer segment 11 c is arranged such that it abuts onthe retainer segment 11 b, that is, such that an end face 21 d of theretainer segment 11 b abuts on an end face 21 e of the retainer segment11 c, and similarly the retainer segments are arranged so as to becontinuously lined with each other, and the retainer segment 11 d isarranged last. Thus, the retainer segments 11 a to 11 d are arranged soas to be continuously lined with each other in the circumferentialdirection. In this case, a circumferential clearance 39 a is providedbetween the first retainer segment 11 a and the last retainer segment 11d.

Next, a description will be made of the circumferential clearancebetween the first retainer segment 11 a and the last retainer segment 11d. FIG. 1 is an enlarged sectional view showing a part I in FIG. 5.Here, a circumferential range R of the clearance 39 a is to be largerthan 0.075% of the circumference of a circle passing through the centerof the retainer segments 11 a to 11 d but smaller than 0.12% thereof. Inthis case, the circumferential range R of the clearance 39 a can belimited to the above range by adjusting the circumferential lengths ofthe retainer segments 11 a to 11 d, or by cutting an end face 21 f ofthe last retainer segment 11 d after the retainer segments 11 a to 11 chave been arranged so as to be continuously lined with each other.

FIG. 7 is a graph showing a relation between a safe ratio of theretainer and a circumferential range of a clearance 39 a. Referring toFIGS. 1 and 7, the safe ratio of the retainer composed of the pluralityof retainer segments 11 a to 11 d is required to be 4.0 or more in viewof fatigue strength of the material of the retainer segments 11 a to 11d and stress generated in the retainer segments 11 a to 11 d. Here, whenthe circumferential range of the clearance 39 a is set to be smallerthan 0.12% of the circumference, the safe ratio can be surely 4.0 ormore. Thus, a problem in strength due to collision among the retainersegments 11 a to 11 d can be avoided.

Here, a linear expansion coefficient Kb of the retainer segment 11 a isabout 1.5×10⁻⁵/° C. Meanwhile, since the bearing component such as theouter ring is formed of case-hardening steel, its linear expansioncoefficient Ka is about 1.12×10⁻⁵/° C. When it is assumed that atemperature rise is Δt and a difference in expansion amount between theabove components is δ, the difference δ is expressed by a formula 1.δ=2πr·(Kb−Ka)·Δt  [Formula 1]

In this case, even when it is assumed that only the retainer segment 11a is raised to 50° C., the difference δ in expansion amount is 0.075%.In addition, even when the tapered roller bearing is heated such thatΔt=100° C. at the time of shrink fitting, the difference δ in expansionamount is 0.035%. Therefore, the difference in expansion amount betweenthe bearing components such as the outer ring 32 a and the inner ring 33a, and the retainer segments 11 a to 11 d is allowable by setting theclearance to be larger than 0.075% in practical usage. Thus, the statein which the circumferential range of the clearance 39 a shows anegative value and the retainer segments 11 a to 11 d push each othercan be avoided. Thus, the retainer segments 11 a to 11 d can beprevented from being deformed due to pushing.

As described above, as the retainer segments 11 a to 11 d are formed ofthe resin containing the filler material to lower the thermal linearexpansion coefficient, and the circumferential clearance 39 a betweenthe retainer segments 11 a and 11 d is within the above range, thetrouble in strength due to collision of the retainer segments 11 a to 11d, and deformation of the retainer segments 11 a to 11 d due tocircumferential pushing can be prevented. Therefore, the function of thetapered roller bearing 31 a having the above retainer segments 11 a to11 d can be prevented from being lowered.

In addition, according to the above retainer segments 11 a to 11 d,since the difference in thermal linear expansion coefficient from thebearing component such as the outer ring 32 a in the tapered rollerbearing 31 a can be small, the dimensional change of the circumferentialclearance 39 a due to the temperature change can be small. Thus, thecircumferential clearance 39 a between the retainer segments 11 a and 11d can be maintained within the set range. Therefore, the function of thetapered roller bearing 31 a provided with the retainer segments 11 a to11 d can be prevented from being lowered.

In addition, an intermediate element to adjust the circumferential rangeR of the clearance 39 a may be provided between the first retainersegment 11 a and the last retainer segment 11 d so as to abut on thelast retainer segment 11 d. In this case, the clearance 39 a isgenerated between the intermediate element and the first retainersegment 11 a. In this constitution, the circumferential range of theclearance 39 a between the first retainer segment 11 a and the lastretainer segment 11 d can be more easily within the above range. Inaddition, in this case, the intermediate element is to be regarded asthe retainer segment. In addition, since the circumferential range ofthe intermediate element is very small as compared with thecircumferential range of the arranged retainer segments 11 a to 11 d,the intermediate element may be formed of the same material as that ofthe retainer segments 11 a to 11 d, or metal, or a resin.

FIGS. 8 and 9 show one example of the main shaft support structure ofthe wind power generator, in which the tapered roller bearing accordingto one embodiment of the present invention is applied as a main shaftsupport bearing 75. A casing 63 of a nacelle 62 for supporting the mainpart of the main shaft support structure is put on a support table 60through a slewing bearing 61 at a high position so as to be horizontallyturned. A blade 67 receiving wind power is fixed to one end of a mainshaft 66. The main shaft 66 is rotatably supported in the casing 63 ofthe nacelle 62 through a main shaft support bearing 65 incorporated in abearing housing 64, and the other end of the main shaft 66 is connectedto a speed-up gear 68, and an output shaft of the speed-up gear 68 iscoupled to a rotor shaft of a generator 69. The nacelle 62 is turned inany angle by a rotation motor 70 through a speed-down gear 71.

The main shaft support bearing 65 assembled in the bearing housing 64 isthe tapered roller bearing according to one embodiment of the presentinvention, and it has the outer ring, the inner ring, the plurality oftapered rollers arranged between the outer ring and the inner ring, andthe plurality of retainer segments having the pocket to house thetapered roller and arranged so as to be continuously lined with eachother in the circumferential direction between the outer ring and theinner ring. The retainer segment is formed of the resin containing thefiller material to lower the thermal linear expansion coefficient. Afterthe plurality of retainer segments have been arranged in thecircumferential direction with no clearance, the clearance is providedbetween the retainer segment arranged first and the retainer segmentarranged last. Here, at room temperature, the circumferential range ofthe clearance is larger than 0.075% of the circumference of the circlepassing through the center of the retainer segments and smaller than0.12% thereof.

Since the main shaft support bearing 65 supports the main shaft 66having one end to which the blade 67 receiving high wind power is fixed,it needs to receive high moment load, thrust load, and radial load.Here, when the roller is the tapered roller, the bearing can receive thehigh moment load and the like.

In addition, according to the main shaft support structure of the abovewind-power generator, since the tapered roller bearing having thefunction prevented from being lowered is contained, the function of themain shaft support structure of the wind-power generator itself can beprevented from being lowered.

In addition, although the circumferential range of the clearance islarger than 0.075% of the circumference of the circle passing throughthe center of the retainer segments and smaller than 0.12% thereof atroom temperature in the above embodiment, the circumferential range ofthe clearance may be larger than 0.075% of the circumference of thecircle passing through the center of the retainer segments and smallerthan 0.10% thereof. In this case, since the safe ratio of the retainercan be 6.0 or more, the deformation due to collision can be furtherprevented.

In addition, although the filler material contained in the resin iscomposed of carbon fiber only to be used as the material of the retainersegment in the above embodiment, a filler material may be composed ofglass fiber only. Instead, a filler material may contain carbon fiberand glass fiber. In addition, a powdery filler material such as carbonblack or a granular filler material may be used.

In addition to the above constitution, the retainer segment may have theplurality of column parts extending along the rotation axis of thebearing so as to form the pockets to hold the rollers, and theconnection parts extending in the circumferential direction so as toconnect the plurality of column parts, and the retainer segment guidesthe rollers, and one guide click having the contact part with the rollerand a recess part formed at the contact part on the circumferentialinner side may be provided at the side wall surface of the column part.

FIG. 10 is a perspective view showing a retainer segment 11 g providedin a tapered roller bearing according to another embodiment of thepresent invention. FIG. 11 is a sectional view showing the retainersegment 11 g in FIG. 10 cut along a line XI-XI in FIG. 10. FIG. 12 is asectional view showing the retainer segment 11 g in FIG. 10 cut by aplane containing a line XII-XII in FIG. 10 and crossing the rotationaxis of the bearing at right angles. FIG. 13 is a sectional view showingthe retainer segment 11 g in FIG. 10 cut by a plane passing through thecenter of the column part 14 g and crossing the circumferentialdirection at right angles. FIG. 14 is an enlarged sectional view showinga pocket of the retainer segment 11 g in FIG. 12. In addition, taperedrollers 12 g, 12 h, and 12 i held by the retainer segment 11 g are shownby a dotted line in FIGS. 12 and 13, and shown by a solid line in FIG.14 to be easily understood. In addition, the recess part that will bedescribed below is not shown in FIGS. 10 and 12. In addition, a PCD 22 gis shown by a one-dot chain line.

A constitution of the retainer segment 11 g contained in the taperedroller bearing will be described with reference to FIGS. 10 to 14. Theretainer segment 11 g is a segment of one annular retainer split by asplit line extending along the rotation axis of the bearing and has atleast one pocket to contain the roller. The retainer segment 11 gincludes four column parts 14 g, 14 h, 14 i, and 14 j extending alongthe rotation axis of the bearing, and a pair of connection parts 15 gand 15 h positioned at axial both ends and extending in acircumferential direction so as to connect the four column parts 14 g to14 j so that pockets 13 g, 13 h, and 13 i to hold the tapered rollers 12g, 12 h, and 12 i are formed. Here, according to the retainer segment 11g, the column parts 14 g and 14 h are positioned at its circumferentialouter side ends.

The connection parts 15 g and 15 h have predetermined curvature radiusesin the circumferential direction so that the plurality of taperedrollers 11 g are arranged so as to be continuously lined with each otherin the circumferential direction to form one annular retainer afterassembled in the tapered roller bearing. According to the connectionparts 15 g and 15 h, the curvature radius of the connection part 15 gpositioned on a small diameter side of the tapered rollers 12 g to 12 iis smaller than the curvature radius of the connection part 15 hpositioned on a large diameter side of the tapered rollers 12 g to 12 i.

According to the column parts 14 g and 14 h positioned oncircumferential both sides of the pocket 13 g, and the column parts 14 iand 14 j positioned on circumferential both sides of the pocket 13 i,guide clicks 17 g, 17 h, 17 i, and 17 j are provided on the innerdiameter side of the side wall surfaces of the column parts 14 g to 14 jto regulate the movement of the retainer segment 11 g toward the radialouter side. The guide clicks 17 g to 17 j are in contact with thetapered rollers 12 g and 12 i held in the pockets 13 g and 13 i, on theinner diameter side. In addition, according to the column parts 14 h and14 i positioned on circumferential both sides of the pocket 13 h, guideclicks 18 h and 18 i are provided on the outer diameter side of the sidewall surfaces of the column parts 14 h and 14 i to regulate the movementof the retainer segment 11 g toward the radial inner side. The guideclicks 18 h and 18 i are in contact with the tapered roller 12 h held inthe pocket 13 h, on the outer diameter side. The guide clicks 17 g to 17j, 18 h, and 18 i are provided at the side wall surfaces of the columnparts 14 g to 14 j, respectively. The guide clicks 17 g to 17 j, 18 h,and 18 i project toward the pockets 13 g to 13 i, respectively. Inaddition, as shown in the section in FIG. 12, each guide surface of theguide clicks 17 g to 17 j, 18 h, and 18 i is arc-shaped in section tofollow each rolling surface of the tapered rollers 12 g to 12 i. Thelength of the guide clicks 17 g to 17 j, 18 h, and 18 i in the rollerlength direction is a little shorter than the length of the pockets 13 gto 13 i in the roller length direction, and provided over almost anentire length of the pockets 13 g to 13 i in the roller lengthdirection. In addition, the guide clicks 17 g to 17 j, 18 h, and 18 iare not provided at one-sided position to the connection part 15 g orthe connection part 15 h, but positioned in the center in the rollerlength direction, at the side wall surfaces of the column parts 14 g to14 j. In addition, end faces 21 g and 21 h provided on thecircumferential outer side of the column parts 14 g and 14 j positionedon the circumferential outer side are flat.

Thus, since the guide clicks 17 g to 17 j, 18 h, and 18 i are providedon the inner diameter side and the outer diameter side, the retainersegment 11 g can guide the rollers such that the rollers are in contactwith contact parts 28 g of the guide surfaces of the guide clicks 17 gto 17 j, 18 h, and 18 i.

At the side wall surface of the column part 14 h provided with the guideclick 18 h, a recess part 29 g is formed by shrinkage generated when theretainer segment 11 g is molded and positioned on the circumferentialinner side of the contact part 28 g that is in contact with the taperedroller 12 h (refer to FIGS. 11 and 14). The recess part 29 g can beeasily formed at the time of injection molding without performing apost-process. More specifically, a mold configuration is made to berecessed at a part corresponding to the contact part 28 g taking theshrinkage into consideration. Thus, the contact part 28 g becomes flatdue to the shrinkage, and the recess part 29 g is generated on thecircumferential inner side of the contact part 28 g due to theshrinkage. Thus, the retainer segment 11 g is produced. In this case,since only one guide click 18 h is provided at the side wall surface ofthe column part 14 h, the recess part 29 g is generated at the positiondescribed above due to the shrinkage. In addition, according to therecess part 29 g formed as described above, its surface roughness isdifferent from that of a recess part formed by a machining process afterthe injection molding. In addition, the recess parts 29 g are alsopositioned on the circumferential inner side of the contact parts thatare in contact with the tapered rollers at the side wall surfaces of thecolumn parts 14 g to 14 j in which the guide clicks 17 g to 17 j areprovided on the inner diameter side and the guide click 18 i is providedon the outer diameter side. Since their constitutions are the same asthe above, their description will be omitted. In addition, the recessedamount of the recess part 29 g is shown in FIG. 13 with exaggeration tobe easily understood.

According to the retainer segment 11 g, since the guide clicks 17 g to17 j, 18 h, and 18 i are provided at the side wall surfaces of thecolumn parts 14 g to 14 j, respectively, the number of the edge parts ofthe guide clicks 17 g to 17 j, 18 h, and 18 i can be small. Since theretainer segment 11 g has the simple configuration, its thicknessdifference is small and the internal defect and deformation areprevented from being generated at the time of injection molding. Inaddition, since contact areas between the tip ends of the guide clicks17 g to 17 j, 18 h, and 18 i and the tapered rollers 12 g to 12 i can belarge, a surface pressure at the time of contact can be lowered.Furthermore, the rigidity of the column parts 14 g to 14 j and thus theretainer segment 11 g can be high. According to the roller bearinghaving the retainer segment 11 g, the postures of the tapered rollers 12g to 12 j and the retainer segment 11 g can be stable. In addition,since the recess part 29 g is positioned on the circumferential innerside of the contact part 28 g, lubricant oil can pool in the recess part29 g. Thus, since the lubricant oil can be supplied from the recess part29 g to the contact part, lubricating properties can be improved.Therefore, the retainer segment 11 g can be prevented from beingdamaged, and the tapered rollers 12 g to 12 i can roll smoothly.

In addition, since the recess part 29 g is smoothly continued to thesurfaces of the guide clicks 17 g to 17 j, 18 h, and 18 i, the lubricantoil can be easily flow in and flow out. In addition, since stressconcentration is not likely to be generated in the recess part 29 ghaving the above configuration, damage can be reduced.

In addition, since the length of the guide clicks 17 g to 17 j, 18 h,and 18 i in the roller length direction is roughly equal to the entirelength of the pockets 13 g to 13 i in the roller length direction, thecontact parts 28 between the tapered rollers 12 g to 12 i and the guideclicks 17 g to 17 j, 18 h, and 18 i can be large, so that the posturesof the tapered rollers 12 g to 12 i and the retainer segment 11 g can bestabilized. Therefore, the tapered rollers 12 g to 12 i can rollsmoothly. Furthermore, since the guide clicks 17 g to 17 j, 18 h, and 18i are provided in the center of the side wall surfaces of the columnparts 14 g to 14 j in the roller length direction, they are in contactwith the tapered rollers 12 g to 12 i contained in the pockets 13 g to13 i, in the center of the roller length, so that the postures of thetapered rollers 12 g to 12 i and the retainer segment 11 g can be morestabilized. Therefore, the tapered rollers 12 g to 12 i can rollsmoothly.

Here, the configuration of the guide click 18 h on the outer diameterside will be described in more detail. FIG. 15 is an enlarged sectionalview showing a part XV in FIG. 14. Referring to FIGS. 10 to 15, an angleof a corner part 23 g of the guide click 18 h positioned in the pocket13 h is made to be an obtuse angle. More specifically, in the sectionshown in FIG. 15, that is, in the section cut by a plane passing throughthe guide click 18 h and crossing the rotation axis of the bearing atright angles, an angle θ₁ formed by a line of a surface 25 g extendingfrom an outer diameter surface 24 g of the column part 14 h toward theinner side of the pocket 13 h so as to form the corner part 23 g, and aline of a tangential surface 27 g at the corner part 23 g in anarc-shaped guide surface 26 g constituting the guide click 23 g is madeto be more than 90°.

When the angle of the corner part 23 g is an acute angle, a large amountof lubricant oil in the vicinity of the tapered roller 12 h and theguide click 18 h is scraped off at the time of the rolling of thetapered roller 12 h. In this case, the lubricant oil is not likely to besupplied from the outer side of the retainer segment 11 g to the pocket13 h, which causes a lubrication defect and hinders the smooth rollingof the tapered roller 12 h.

However, since the corner part 23 g positioned at the tip end of theguide click 18 h has the obtuse angle, the scraped amount of thelubricant oil in the vicinity of the tapered roller 12 h and the guideclick 18 h can be small at the time of the rolling of the tapered roller12 h. Thus, the lubricant oil in the vicinity of the tapered roller 12 hand the guide click 18 h can be likely to be supplied to the pocket 13h, and the lubrication defect is prevented. Therefore, the taperedroller 12 h can roll smoothly. In addition, since the guide clicks 17 gto 17 j on the inner diameter side and the guide click 18 i on the outerdiameter side have the same constitution, their description will beomitted.

Next, a description will be made of a constitution of the tapered rollerbearing containing the retainer segment 11 g. FIG. 16 is a schematicsectional view showing a tapered roller bearing 31 g in which theplurality of retainer segments 11 g, 11 h, 11 i, and 11 j are arrangedin a circumferential direction, taken from an axial direction. Inaddition, FIG. 17 is an enlarged sectional view showing a part XVII inFIG. 16. Here, since the retainer segments 11 h, 11 i, and 11 j have thesame configuration as the retainer segment 11 g, their description willbe omitted. In addition, in FIG. 16, the tapered roller held in theretainer segment 11 g is omitted, and in FIGS. 16 and 17, the recesspart provided at the side wall surface of the column part is omitted. Inaddition, here, it is assumed that the retainer segment arranged firstis the retainer segment 11 g, and the retainer segment arranged last isthe retainer segment 11 j among the plurality of retainer segments 11 gto 11 j.

Referring to FIGS. 16 and 17, the tapered roller bearing 31 g includesan outer ring 32 g, an inner ring 33 g, a plurality of tapered rollers34 g, and the plurality of retainer segments 11 g to 11 j. The retainersegments 11 g to 11 j are arranged so as to be continuously lined witheach other in the circumferential direction with no clearance. Here, theretainer segment 11 g is arranged first, and then the retainer segment11 h is arranged such that the retainer segment 11 h abuts on theretainer segment 11 g, that is, such that the end face 21 g of theretainer segment 11 h abuts on an end face 21 i of the retainer segment11 h. Then, the retainer segment 11 i is arranged such that it abuts onthe retainer segment 11 h, that is, such that an end face 21 j of theretainer segment 11 h abuts on an end face 21 k of the retainer segment11 i, and similarly the retainer segments are arranged so as to becontinuously lined with each other, and the retainer segment 11 j isarranged last. Thus, the retainer segments 11 g to 11 j are arranged soas to be continuously lined with each other in the circumferentialdirection. In this case, a circumferential clearance 39 g is providedbetween the first retainer segment 11 g and the last retainer segment 11j. The clearance 39 g is provided taking the thermal expansion of theretainer segments 11 g to 11 j into consideration.

Here, as described above, since the shrinkage is not likely to begenerated at the tip ends of guide clicks 36 g and 37 g provided at theside wall surfaces of the column parts, the rigidity of the column partis high, and a surface pressure at the time of contact can be lowered byincreasing the contact areas between the tip ends of the guide clicks 36g and 37 g, and the tapered roller 34 g. In addition, lubricant oil canbe supplied from the recess part positioned on the circumferential innerside of the contact part to the contact part, so that lubricationproperties can be improved. Since the recess part is smoothly continuedto each surface of the guide clicks 36 g and 37 g, the lubricant oil canbe easily flow in and flow out. In addition, since stress concentrationis not likely to be generated in the recess part having the aboveconfiguration, damage can be reduced. Therefore, the retainer segment 11h is prevented from being damaged and the tapered roller 34 g can rollsmoothly.

Furthermore, an angle of a corner part positioned at the tip ends of theguide clicks 36 g and 37 g provided in the retainer segment 11 h is anobtuse angle. Thus, the scraped amount of the lubricant oil in thevicinity of the tapered roller 34 g and the guide clicks 36 g and 37 gby the corner part positioned at the tip ends of the guide clicks 36 gand 37 g can be reduced at the time of the rolling of the tapered roller34 g. Thus, the lubricant oil in the vicinity of the tapered roller 34 gand the guide clicks 36 g and 37 g can be likely to be supplied to thepocket, and the lubrication defect is prevented.

In addition, the corner parts of the guide clicks 36 g and 37 g may bechamfered. In this case, the scraped amount of the lubricant oil at thecorner part can be further reduced. Therefore, the tapered roller 34 gcan roll more smoothly.

Furthermore, as shown in FIG. 18, a corner part 42 g of a guide click 41g may be R-chamfered. In this case, since the corner part 42 g becomessmoother, the scraped amount of the lubricant oil can be furtherreduced.

In addition, the retainer segment guiding the rollers may have aconstitution in which one guide click is provided in the center of theside wall surface of the column part in a roller length direction, andthe recess part positioned on the circumferential inner side of thecontact part of the guide click is formed by the shrinkage. In addition,the retainer segment guiding the rollers may have a constitution inwhich one guide click having a length roughly equal to the entire lengthof the pocket in the roller length direction is provided at the sidewall surface of the column part, and the recess part positioned on thecircumferential inner side of the contact part of the guide click isformed by the shrinkage. In addition, the retainer segment guiding therollers may have a constitution in which one guide click having thecorner part at its tip end made to have the obtuse angle is provided atthe side wall surface of the column part, and the recess part positionedon the circumferential inner side of the contact part of the guide clickis formed by the shrinkage. In addition, the corner part may bechamfered and the chamfered part may be R-chamfered.

In addition, although the recess part formed on the circumferentialinner side of the contact part is formed by use of the shrinkage in theabove embodiment, the recess part may be formed on the circumferentialinner side of the contact part by a machining process.

In addition, the tapered roller bearing may be applied to the main shaftsupport bearing of the main shaft support structure of the wind-powergenerator shown in FIGS. 8 and 9.

More specifically, the main shaft support bearing assembled in thebearing housing is the tapered roller bearing according to anotherembodiment of the present invention, and includes the outer ring, theinner ring, and the plurality of tapered rollers arranged between theouter ring and the inner ring, and the plurality of retainer segmentshaving the plurality of column parts extending along the rotation axisof the bearing so as to form the pockets to house the tapered rollers,and the connection part extending in the circumferential direction so asto connect the plurality of column parts, and arranged so as to becontinuously lined with each other in the circumferential directionbetween the outer ring and the inner ring. The retainer segment guidesthe rollers. Here, one guide click having the contact part with thetapered roller, and the recess part formed on the circumferential innerside of the contact part are provided at the side wall surface of thecolumn part.

Since the main shaft support bearing supports the main shaft having oneend to which the blade receiving high wind power is fixed, it needs toreceive high moment load, thrust load, and radial load. Here, when theroller is the tapered roller, the bearing can receive the high momentload and the like.

In addition, since the main shaft support structure of the wind-powergenerator has the tapered roller bearing in which the retainer segmentis prevented from being damaged and the tapered roller roll smoothly, ithas a long life.

Next, when the above tapered roller bearing is a double-row taperedroller bearing, an assembling method of the double-row tapered rollerbearing in the rotation shaft will be described.

In general, when a large tapered roller bearing is assembled in therotation shaft extending in a vertical direction, the inner ring isarranged with its large-diameter side end face down, and the taperedroller and the retainer are arranged on a track surface of the innerring. Then, the inner ring having the tapered roller and the retainerare hoisted with a crane and the like to be assembled in the rotationshaft.

Here, when the inner ring is hoisted with its small-diameter side endface down, the tapered roller and the retainer escape from the innerring. In this case, according to a retainer composed of one annularpart, the tapered roller can be prevented from escaping by connectingthe inner ring and the retainer fixedly. However, the above-describedretainer segments are arranged in the circumferential direction and eachof them is an independent member. Thus, since it is necessary to connectthe inner ring and each retainer segment fixedly to prevent the taperedroller from escaping, a large amount of labor is required. As a result,it becomes difficult to assemble the inner ring having the taperedroller and the retainer, in the rotation shaft, so that the productivityof the tapered roller bearing is lowered.

Here, a double-row tapered roller bearing according to still anotherembodiment of the present invention may be constituted as follows.

FIG. 19 is a sectional view showing the double-row tapered rollerbearing according to still another embodiment of the present invention.FIG. 20 is an enlarged sectional view showing a part XX in FIG. 19.Referring to FIGS. 19 and 20, a double-row tapered roller bearing 41includes an outer ring 42, two inner rings 43 a and 43 b arranged suchthat small-diameter side ends 48 a and 48 b are opposed, a plurality oftapered rollers 44 a and 44 b arranged between the outer ring 42 and theinner rings 43 a and 43 b, a plurality of retainer segments 45 a and 45b retaining the tapered rollers 44 a and 44 b, respectively as describedabove and an intermediate element (not shown), and an inner ringintermediate element 46 arranged between the inner ring 43 a and theinner ring 43 b.

Two track surfaces 51 a and 51 b are provided at the outer ring 42. Inaddition, the inner rings 43 a and 43 b have track surfaces 51 c and 51d, respectively. The tapered roller 44 a is arranged between the outerring 42 and the inner ring 43 a such that its rolling surface 52 a abutson the track surfaces 51 a and 51 c. Similarly, the tapered roller 44 bis arranged between the outer ring 42 and the inner ring 43 b such thatits rolling surface 52 b abuts on the track surfaces 51 b and 51 d.

Here, the outer ring 42 has small flanges 49 a and 49 b at thesmall-diameter side ends of the tapered rollers 44 a and 44 b. When thedouble-row tapered roller bearing 41 is assembled, guide surfaces 50 aand 50 b of the small flanges 49 a and 49 b can abut on small end faces53 a and 53 b of the tapered rollers 44 a and 44 b, respectively. Inaddition, it is preferable that the guide surface 50 a is roughlyorthogonal to the track surface 51 a, or roughly parallel to the smallend face 53 a after the tapered roller 44 a has been arranged.Similarly, it is preferable that the guide surface 50 b is roughlyorthogonal to the track surface 51 b, or roughly parallel to the smallend face 53 b after the tapered roller 44 b has been arranged.

The inner ring 43 a has a large flange 55 a at the large-diameter sideend of the tapered roller 44 a but does not have a small flange at thesmall-diameter side end 48 a. More specifically, although the largeflange 55 a is provided at the large-diameter side end of the inner ring43 a, the small flange is not provided at the small-diameter side end 48a of the inner ring 43 a. A maximum outer diameter L₁ of thesmall-diameter side end 48 a of the inner ring 43 a is not more than aninscribed circle diameter L₂ of the tapered roller 44 a (refer to FIG.20). In addition, the inner ring 43 b has a large flange 55 b at thelarge-diameter side end of the tapered roller 44 b but does not have asmall flange at the small-diameter side end 48 b similar to the innerring 43 a.

FIG. 21 is a flowchart showing procedures when the double-row taperedroller bearing 41 shown in FIGS. 19 and 20 is assembled in a rotationshaft 47. In addition, FIGS. 22 to 26 are sectional views showingarrangement of members in the processes. A description will be made ofan assembling method for assembling the above double-row tapered rollerbearing 41 in the rotation shaft 47.

First, one inner ring 43 b is assembled in the rotation shaft 47 with alarge-diameter side end face 56 b down (FIG. 21(A) and FIG. 22). Then,the tapered roller 44 b and the retainer segment 45 b are arranged suchthat the track surface 51 d of the inner ring 43 b abuts on the rollingsurface 52 b of the tapered roller 44 b, and the guide surface 50 d ofthe large flange 55 b of the inner ring 43 b abuts on a large end face54 b of the tapered roller 44 b (FIG. 21(B) and FIG. 23). The taperedroller 44 b and the retainer segment 45 b are arranged on a tracksurface 51 d of the inner ring 43 b such that the plurality of retainersegments 45 b are arranged so as to be continuously lined with eachother in the circumferential direction as described above (FIG. 21(B)and FIG. 23). Then, an intermediate element is arranged between thefirst retainer segment 45 b and the last retainer segment 45 b. In thiscase, since the large end face 54 b of the tapered roller 44 b isarranged so as to abut on the guide surface 50 d of the large flange 55b of the inner ring 43 b, the large end face 54 b is caught by the largeflange 55 b, so that the arrangement of the tapered roller 44 b and theretainer segment 45 b is fixed.

Then, the inner ring intermediate element 46 is assembled in therotation shaft 47 from the above so as to abut on the small-diameterside end 48 b of the inner ring 43 b (FIG. 21(C) and FIG. 24).

Then, the outer ring 42 is arranged from the above such that the rollingsurface 52 b of the tapered roller 44 b abuts on the track surface 51 bof the outer ring 42, and the guide surface 50 b of the small flange 49b abuts on the small end face 53 b of the tapered roller 44 b (FIG.21(D) and FIG. 25). In this case, since the small flange 49 b is caughtby the small end face 53 b of the tapered roller 44 b, the arrangementof the outer ring 42 is fixed.

Then, the tapered roller 44 a and the retainer segment 45 a are arrangedsuch that the track surface 51 a of the outer ring 42 abuts on the tracksurface 52 a of the tapered roller 44 a, and the guide surface 50 a ofthe small flange 49 a abuts on the small end face 53 a of the taperedroller 44 a (FIG. 21(E) and FIG. 26). In this case also, the retainersegments 45 a and the like are arranged so as to be continuously linedwith each other in the circumferential direction. In addition, in thiscase also, since the small end face 53 a of the tapered roller 44 a iscaught by the small flange 49 a, the arrangement of the tapered roller44 a and the retainer segment 45 a is fixed.

Then, the inner ring 43 a is assembled in the rotation shaft 47 from theabove with a large-diameter end face 56 a of the inner ring 43 a up suchthat the rolling surface 52 a of the tapered roller 44 a abuts on thetrack surface 51 c of the inner ring 43 a (FIG. 21(F) and FIGS. 19 and20). In this case, since the small flange is not provided at thesmall-diameter side end 48 a of the inner ring 43 a, the tapered roller44 a and the inner ring 43 a do not interfere with each other. Inaddition, since the maximum outer diameter L₁ of the small-diameter sideend 48 a of the inner ring 43 a is not more than the inscribed circlediameter L₂ of the tapered roller 44 a, when the inner ring 43 a isassembled in the rotation shaft 47, the small-diameter side end 48 a ofthe inner ring 43 a does not interfere with the tapered roller 44 a.

In addition, although the small end faces 53 a and 53 b of the taperedrollers 44 a and 44 b abut on the guide surfaces 50 a and 50 b of thesmall flanges 49 a and 49 b in the assembled state, when a load isapplied to the double-row tapered roller bearing 41, an induced thrustload is generated, and large end faces 54 a and 54 b of the taperedrollers 44 a and 44 b abut on guide surfaces 50 c and 50 d of the largeflanges 55 a and 55 b.

According to the above constitution, an assembling property of thedouble-row tapered roller bearing 41 is improved. Consequently,according to the assembling method of the above double-row taperedroller bearing 41, the arrangement of the tapered roller 44 a and theretainer segment 45 a can be prevented from collapsing, due to the smallflange 49 a provided at the outer ring 42. In addition, since the smallflange is not provided in the small-diameter side end 48 a of the innerring 43 a, the inner ring 43 a and the tapered roller 44 a do notinterfere with each other when the inner ring 43 a is assembled.Therefore, the assembling property is improved.

In addition, it is preferable that a distance L₃ between the guidesurface 50 c of the large flange 55 a of the inner ring 43 a and theguide surface 50 a of the small flange 49 a in the roller lengthdirection is longer than a length L₄ of the tapered roller 44 a (referto FIG. 20). Thus, since the rolling surface 52 a of the tapered roller44 a can appropriately abut on the track surfaces 51 a and 51 c of theouter ring 42 and the inner ring 43 a, respectively, the load can bereceived by the tapered roller 44 a appropriately. In addition, it ispreferable that a length between the guide surface 50 d of the largeflange 55 b and the guide surface 50 b of the small flange 49 b, and thelength of the tapered roller 44 b have the same relation as describedabove.

In addition, it is preferable that the outer diameter of thesmall-diameter side end of the inner ring is decreased toward its tipend. For example, it is preferable that an angle formed between a lineof the outer diameter surface at the small-diameter side end and therotation center axis is more than 0° in a section passing through therotation center axis FIG. 27 is an enlarged sectional view showing thevicinity of a small-diameter side end of an inner ring contained in thedouble-row tapered roller bearing. The section shown in FIG. 27 passesthrough the rotation center axis. Referring to FIG. 27, it is preferablethat an angle θ₂ formed between a line 57 a of an outer diameter surfaceat a small-diameter side end 48 c and a line 57 b parallel to therotation center axis is more than 0°. Thus, the outer diameter of thesmall-diameter side end 48 c of an inner ring 43 c can be decreasedtoward the tip end. Therefore, the inner ring 43 c can be smoothlyassembled when the inner ring 43 c is assembled in the rotation shaft47. In addition, the outer diameter surface may be composed of aplurality of flat surfaces and curved surfaces to decrease the outerdiameter toward the tip end.

In addition, a corner part of the outer diameter surface of thesmall-diameter side end of the inner ring may be chamfered. FIG. 28 isan enlarged sectional view showing one part of an inner ring in thiscase, and corresponds to FIG. 27. Referring to FIG. 28, a corner part 58of an outer diameter surface of a small-diameter side end 48 d of aninner ring 43 d is chamfered so as to have a R configuration insectional view. Thus, when the inner ring 43 d is assembled in therotation shaft 47, its handling property and assembling property areimproved. In addition, the corner part may be C-chamfered.

In addition, the above tapered roller bearing may be applied to the mainshaft support bearing of the main shaft support structure of thewind-power generator shown in FIGS. 8 and 9.

More specifically, the main shaft support bearing 65 assembled in thebearing housing 64 is the tapered roller bearing according to stillanother embodiment of the present invention, and it has the taperedrollers, the outer ring having the small flange at the small-diameterside end of the tapered roller, the inner ring not having the smallflange at the small-diameter side end of the tapered roller, and theplurality of retainer segments having at least one pocket to hold thetapered roller, and split in the circumferential direction.

Since the main shaft support bearing 65 supports the main shaft 66having one end fixed to the blade 67 receiving great wing power, a highload is applied to it, so that the bearing itself has to be large. Here,since the retainer is the split type and has the above constitution, thetapered roller bearing can be easily assembled in the main shaft.Therefore, the productivity of the main shaft support structure of thewind-power generator can be improved.

In addition, although the double-row tapered roller bearing is used inthe above embodiment, the present invention is not limited to this, sothat a single-row tapered roller bearing may be used. In addition,although the above tapered roller bearing includes the intermediateelement, the present invention is not limited to this, so that thetapered roller bearing may not include the intermediate element. Inaddition, although the retainer segment contained in the tapered rollerbearing has the configuration split by the split line extending alongthe shaft in the above, the retainer segment may have any configurationsplit in the circumferential direction.

In addition, the tapered roller bearing according to still anotherembodiment of the present invention may have a configuration in which itincludes the inner ring, the outer ring, the plurality of taperedrollers having the rolling surfaces that are in contact with the innerring and the outer ring, and the plurality of retainer segments havingthe plurality of column parts extending along the shaft so as to formthe pockets to hold the tapered rollers and the connection partsextending in the circumferential direction so as to connect theplurality of column parts, and arranged so as to be continuously linedwith each other in the circumferential direction between the inner ringand the outer ring, and when it is assumed that a roller diameter of thetapered roller at a certain position of the rolling surface is D, and adistance between the track surfaces of the inner ring and the outer ringat the measurement position of the roller diameter of the tapered rolleris d, a relation D>d is satisfied in at least one position of therolling surface of each tapered roller.

When the distance d between the track surfaces is smaller than thediameter D at any position of the tapered roller bearing in thecircumferential direction (this relation is referred to as the “negativeclearance” hereinafter), the tapered roller is prevented from slippinglaterally, and its rotation movement and revolution movement becomesmooth. As a result, since the adjacent retainer segments are preventedfrom colliding with each other, a noise and abrasion due to thecollision are prevented, and the retainer is prevented from beingdeformed and damaged.

FIGS. 29 and 30 are views showing a tapered roller bearing 81 applied tothe above-described main shaft support bearing of the wind-powergenerator, and FIGS. 31 to 33 are views showing an assembling method forassembling the tapered roller bearing 81 in a main shaft 86.

Referring to FIG. 29, the tapered roller bearing 81 includes an innerring 82 containing right and left inner ring members 82 a and 82 b, anouter ring 83, a plurality of tapered rollers 84, a retainer containinga plurality of retainer segments 91, and an inner ring intermediateelement 85. In addition, since the retainer segment 91 a is the same asthe retainer segment shown in FIG. 2, its description will be omitted.

The inner ring member 82 a has a track surface 86 a on its outerdiameter surface, a small flange 87 a at one side end of the tracksurface 86 a, a large flange 88 a at the other side end thereof, and aplurality of bolt holes 89 a extending in an axial direction at an endface on the side of the large flange 88 a. The inner ring member 82 bhas the same constitution. Thus, the inner ring members 82 a and 82 bare arranged such that their small flanges 87 a and 87 b are opposed toeach other so as to sandwich the inner ring intermediate element 85,whereby the inner ring 82 is formed. The outer ring 83 has double-rowtrack surfaces 83 a and 83 b corresponding to the track surfaces 86 aand 86 b of the inner ring members 82 a ad 82 b, respectively, and aplurality of through holes 83 c penetrating in the axial direction.

Referring to FIG. 30, the tapered roller 84 has a small end face 84 a, alarge end face 84 b, and a rolling surface 84 c, and arranged betweenthe inner ring 82 and the outer ring 83 such that the small end faces 84a are opposed to the small flanges 87 a and 87 b of the inner ringmembers 82 a and 82 b. In addition, a crowning is formed on the rollingsurface 84 c and its top is positioned in the center of the rollerlength. In addition, the “rolling surface” designates a length providedby removing chamfered parts on both ends, and it can be in contact withthe track surfaces 86 a, 86 b, 83 a, and 83 b of the inner ring 82 andthe outer ring 83 when assembled in the bearing.

The tapered roller bearing 81 having the above constitution is aback-to-back bearing in which the tapered rollers 84 are arranged indouble rows in the axial direction and the small end faces 84 a of thetapered rollers 84 in the right and left rows face each other. Inaddition, when it is assumed that a roller diameter of the taperedroller 84 at a certain position of the track surface 84 c of the taperedroller 84 is D, and a distance between the track surfaces of the innerring 82 and the outer ring 83 at the measurement position of the rollerdiameter of the tapered roller 84 is d, a relation D>d is satisfied inat least one position of the track surface 84 c of each tapered roller84. That is, the distance between the track surfaces is a negativeclearance.

More specifically, when a load applied to the tapered roller bearing 81is low (at the time of low load), the track surfaces 86 a and 83 a arein contact with the rolling surface only at the top of the crowning.Consequently, the negative clearance (D₁>d₁) is provided only at the topof the crowning of each tapered roller 84. In addition, the distance d₁designates a distance between the track surfaces at the positioncorresponding to the top of the crowning.

Meanwhile, when a load applied to the tapered roller bearing 81 is high(at the time of high load), the rolling surface 84 c of the taperedroller 84 is elastically deformed and the contact area between the tracksurfaces 86 a and 83 a and the rolling surface 84 c is increased. Whenthe whole area of the rolling surface 84 c is in contact with the tracksurfaces 86 a and 83 a, the negative clearance (D>d) is provided in theentire rolling surface 84 c of the tapered roller 84.

When the distance between the track surfaces is the negative clearanceas described above, the tapered roller 84 is prevented from slippinglaterally, and its rotation movement and revolution movement becomesmooth. As a result, since the adjacent retainer segments are preventedfrom colliding with each other, a noise and abrasion due to thecollision are prevented, and the retainer is prevented from beingdeformed and damaged.

In addition, since the distance between the track surfaces of thetapered roller bearing 81 is the negative clearance, a load is appliedto all the tapered rollers 84 through the inner ring 82 and outer ring83. As a result, even when the tapered roller bearing 81 is used underthe circumstances containing a load region and a non-load region, it cansupport a high load and the rigidity of the tapered roller bearing 81 isimproved. In addition, the “load region” designates a region in which aload is applied in the circumferential direction of the main shaft, andthe “non-load region” designates a region in which a load is notapplied. The load region and the non-load region are provided when aload biased in a predetermined direction is applied at the time ofrotation of the main shaft of the wind-power generator, for example.

When the above tapered roller bearing 81 is used as the bearing tosupport the main shaft of the wind-power generator, the main shaftsupport structure of the wind-power generator can have a long life andcan be highly reliable.

Although the top of the crowning is positioned in the center of theroller length of the tapered roller 84 in the above embodiment, it canbe set at any position. In addition, although the crowning is formed onthe rolling surface 84 c in the above example, the present invention canbe applied to a tapered roller bearing containing a tapered rollerhaving no crowning.

In addition, although the double-row tapered roller bearing 81 is shownin the above embodiment, the present invention can be applied to asingle-row bearing or a bearing having three or more rows of tracksurfaces. In addition, the back-to-back tapered roller bearing 81 isshown in the above, the present invention may be applied to afront-to-front bearing in which the large end faces 84 b of the taperedrollers 84 are opposed to each other.

In the case of the back-to-back bearing, since a distance between pointsα and β at the intersection of a rotation center line l₀ of the bearingwith contact lines l₁ and l₂ of the tapered rollers 84 in the right andleft rows and the inner and outer rings 82 and 83 (referred to as the“distance between the action points” hereinafter) is increased, therigidity is improved.

In addition, it is to be noted that the retainer used in the abovetapered roller bearing includes various kinds of split type retainerscut at a circumferential certain position.

Next, a method for assembling the tapered roller bearing 81 in the mainshaft 86 will be described with reference to FIGS. 31 to 33. Inaddition, FIGS. 31 and 32 are views showing before and after the taperedroller bearing 81 is assembled in the main shaft 86, and FIG. 33 is aflowchart showing main steps to assemble one inner ring member 82 b ofthe tapered roller bearing 81, in the main shaft 86.

When the tapered roller bearing 81 is assembled in the main shaft 86 ofthe large wind-power generator, the main shaft 86 is fixed to the groundvertically. First, the inner ring member 82 a is fit in the main shaft86 with the side of the large flange 88 a down. Then, the retainersegments 91 in which the tapered rollers 84 are housed in the pocket,and the intermediate element (not shown) are arranged so as to becontinuously lined with each other on the track surface 86 a of theinner ring member 82 a. Here, since the tapered roller bearing 81 tosupport the main shaft 86 of the wind-power generator has a largetapered angle in general, the tapered roller 84 is caught by the largeflange 88 a and prevented from escaping without being tied on the tracksurface 86 a. Then, the inner ring intermediate element 85 is fit in themain shaft 86.

Then, referring to FIG. 33, the inner ring member 82 b and the outerring 83 are assembled before assembled in the main shaft 86 (S11). Morespecifically, the inner ring member 82 b is set with the side of thelarge flange 88 b down. Then, the retainer segments 91 in which thetapered rollers 84 are housed in the pocket are arranged so as to becontinuously lined with each other on the track surface 86 b of theinner ring member 82 b. Then, the outer ring 83 is assembled in suchthat the track surface 83 b of the outer ring 83 is appropriately incontact with the track surface 84 c of the tapered roller 84.

Then, the inner ring member 82 b and the outer ring 83 are fixedlyconnected to each other (S12). More specifically, one end of an L-shapedfixing jig and a bolt hole 89 b of the inner ring member 82 b are fixedby a bolt 93, and the other end thereof and the through hole 83 c of theouter ring 83 are fixed by a fixing bar 94. Thus, the tapered roller 84is restrained between the track surfaces 86 b and 83 b and preventedfrom escaping.

Then, as shown in FIG. 31, the inner ring member 82 b and the outer ring83 connected fixedly are lifted (S13), and assembled in the main shaft86 with the side of the track surface 83 a of the outer ring 83 down(S14). Then, as shown in FIG. 32, the fixing jig 92 is removed afterconfirming that the track surface 83 a of the outer ring 83 isappropriately in contact with the tapered roller 84 assembled in theinner ring member 82 a.

Finally, the distance d between the track surfaces of the inner ring 82and the outer ring 83 is adjusted (S15). More specifically, a width ofthe inner ring intermediate element 85 is previously adjusted, and thedistance between the track surfaces is set to a predetermined value byapplying a precompression between the inner ring members 82 a and 82 b.

According to the above assembling procedures, when the tapered rollerbearing 81 is assembled in the main shaft 86, the tapered roller 84 andthe retainer segment 91 are prevented from escaping. Thus, the taperedroller bearing 81 can be easily assembled in the main shaft 86.

In addition, even when the present invention is applied to other typebearings such as a self-aligning roller bearing, the effect of thepresent invention can be achieved. However, since the distance betweenthe track surfaces can be easily adjusted in the tapered roller bearingas described above, the present invention is suitably applied to thetapered roller bearing.

In addition, the above assembling procedures are one example, so thatanother step may be added or the order of the steps may be exchanged. Inaddition, the fixing jig 92 may have any configuration as long as theinner ring member 82 b and the outer ring 83 can be connected and fixed.

Although the bolt holes 89 a and 89 b are provided in the inner ringmembers 82 a and 82 b, respectively in view of general versatility, thebolt hole 89 b may be only provided in the inner ring member 82 b thatis assembled with the side of the small flange 87 b down in the interestof an assembling operation.

Here, the main shaft support structure of the wind-power generatoraccording to the present invention includes the blade receiving windpower, the main shaft having one end fixed to the blade and rotatingtogether with the blade, and the tapered roller bearing to support themain shaft rotatably. The tapered roller bearing has the inner ring, theouter ring, the plurality of tapered rollers having the rolling surfacesthat are in contact with the inner ring and the outer ring, and theplurality of retainer segments having the plurality of column partsextending along the shaft so as to form the pockets to hold the taperedrollers and the connection parts extending in the circumferentialdirection so as to connect the plurality of column parts, and arrangedso as to be continuously lined with each other in the circumferentialdirection between the inner ring and the outer ring. When it is assumedthat the roller diameter of the tapered roller at a certain position ofthe rolling surface is D, and the distance between the track surfaces ofthe inner ring and the outer ring at the measurement position of theroller diameter of the tapered roller is d, the relation D>d may besatisfied in at least one position of the rolling surface of eachtapered roller.

When the above tapered roller bearing is employed, the main shaftsupport structure of the wind-power generator can be highly reliable andhave a long life.

In addition, the main shaft support structure of the wind-powergenerator according to the present invention may employ a main shaftsupport structure of the wind-power generator having the followingconstitution. More specifically, the main shaft support structure of thewind-power generator includes the blade receiving wind power, the mainshaft having one end fixed to the blade and rotating together with theblade, and a tapered roller bearing to support the main shaft rotatably.The tapered roller bearing has an inner ring and an outer ring havingtrack surfaces, and a plurality of tapered rollers having the rollingsurfaces to be in contact with the track surfaces. Thus, the taperedroller bearing is a retainerless roller bearing in which the adjacenttapered rollers are arranged so as to be in contact with each other.

When the retainerless roller bearing having the above constitution isemployed as the bearing to support the main shaft of the wind-powergenerator, the number of the tapered rollers that can be housed can beincreased as compared with the tapered roller bearing of the same sizehaving the retainer. As a result, load capacity of the bearing isincreased as a whole.

FIGS. 34 and 35 show a tapered roller bearing 95 to support the mainshaft 86 of the wind-power generator, and FIGS. 36 to 38 show a methodfor assembling the tapered roller bearing 95 in the main shaft 86.

Referring to FIG. 34, the tapered roller bearing 95 includes an innerring 96 having right and left inner ring members 82 e and 82 f, an outerring 97, a plurality of tapered rollers 98, and an inner ringintermediate element 85.

The inner ring member 82 e has a track surface 86 e on an outer diametersurface, a small flange 87 e at one side end of the track surface 86 e,a large flange 88 e at the other side end thereof, and a plurality ofbolt holes 89 e provided at the end face on the side of the large flange88 e and extending in the axial direction. The inner ring member 82 fhas the same constitution. Thus, the inner ring 96 is constituted byarranging the inner ring members 82 e and 82 f such that the smallflanges 87 e and 87 f are opposed to sandwich the inner ringintermediate element 85. The outer ring 97 has double-row track surfaces83 e and 83 f corresponding to the track surfaces 86 e and 86 f of theinner ring members 82 e and 82 f, respectively, and a plurality ofthrough holes 83 g penetrating in the axial direction.

Referring to FIG. 35, the tapered roller 98 has a small end face 84 e, alarge end face 84 f, and a rolling surface 84 g, and arranged betweenthe inner ring 96 and the outer ring 97 such that the small end faces 84e are opposed to the small flanges 87 e and 87 f of the inner ringmembers 82 e and 82 f. In addition, a crowning is formed on the rollingsurface 84 g, and its top is positioned in the center of the rollerlength.

The above tapered roller bearing 95 is a back-to-back bearing in whichthe tapered rollers 98 are arranged in the axial direction in doublerows and the small end faces 84 e of the tapered rollers 98 in the rightand left rows are opposed to each other. In addition, the bearing 95 isthe retainerless roller bearing in which the adjacent tapered rollers 98are arranged so as to be in contact with each other on each tracksurface.

In addition, when a roller diameter of the tapered roller 98 at acertain position of the track surface 84 g thereof is D, and a distancebetween the track surfaces of the inner ring 96 and the outer ring 97 atthe measurement position of the roller diameter of the tapered roller 98is d, a relation D>d is satisfied in at least one position of the tracksurface 84 g of each tapered roller 98. That is, the distance betweenthe track surfaces is a negative clearance.

More specifically, when a load applied to the tapered roller bearing 95is low (at the time of low load), the track surfaces 86 e and 83 e arein contact with the rolling surface 84 g only at the top of thecrowning. Consequently, the negative clearance (D₁>d₁) is provided onlyat the top of the crowning of each tapered roller 98. In addition, thedistance d₁ designates a distance between the track surfaces at theposition corresponding to the top of the crowning.

Meanwhile, when a load applied to the tapered roller bearing 95 is high(at the time of high load), the rolling surface 84 g of the taperedroller 98 is elastically deformed and the contact area between the tracksurfaces 86 e and 83 e and the rolling surface 84 g is increased. Whenthe whole area of the rolling surface 84 g is in contact with the tracksurfaces 86 e and 83 e, the negative clearance (D>d) is provided overthe entire rolling surface 84 g of the tapered roller 98.

As described above, when the retainerless roller bearing 95 is employed,the number of the tapered rollers 98 that can be housed can be increasedas compared with the tapered roller bearing of the same size having theretainer. As a result, the load capacity of the bearing is increased asa whole. In addition, since the distance between the track surfaces isthe negative clearance, the load is applied to all of the taperedrollers 98 through the inner and outer rings 96 and 97. As a result,even when the tapered roller bearing 95 is used under the circumstancescontaining the load region and the non-load region, it can support ahigh load and its rigidity is improved.

In addition, since the rotation directions of the adjacent taperedrollers 98 at the contact position are opposite to each other, theproblems is that the rotation defect is generated due to theinterference of the adjacent tapered rollers 98 in the retainerlesstapered roller bearing 95. However, since the distance between the tracksurfaces is the negative clearance, the tapered roller 98 can beprevented from slipping laterally, so that the rotation defect due tothe interference between the adjacent tapered rollers 98 can beprevented. As a result, the rotation movement and revolution movement ofthe tapered roller 98 become smooth.

When the above tapered roller bearing 95 is used as the bearing tosupport the main shaft of the wind-power generator, the main shaftsupport structure of the wind-power generator can have a long life andcan be highly reliable.

Although the top of the crowning is positioned in the center of theroller length of the tapered roller 98 in the above embodiment, it canbe set at any position. In addition, the crowning is formed on therolling surface 84 g in the above example, the present invention can beapplied to a tapered roller bearing containing a tapered roller havingno crowning.

In addition, although the double-row tapered roller bearing 95 is shownin the above embodiment, the present invention can be applied to asingle-row bearing or a bearing having three or more rows of tracksurfaces. In addition, the back-to-back tapered roller bearing 95 isshown in the above, the present invention may be applied to afront-to-front bearing in which the large end faces 84 f of the taperedrollers 98 are opposed to each other.

In the case of the back-to-back bearing, since a distance between pointsα and β at intersection of a rotation center line l₀ of the bearing withcontact lines l₁ and l₂ of the tapered rollers 98 in the right and leftrows and the inner and outer rings 96 and 97, that is, the distancebetween the action points is increased, the rigidity is improved.

Next, a method for assembling the tapered roller bearing 95 in the mainshaft 86 will be described with reference to FIGS. 36 to 38. Inaddition, FIGS. 36 and 37 are views showing before and after the taperedroller bearing 95 is assembled in the main shaft 86, and FIG. 38 is aflowchart showing main steps to assemble one inner ring member 82 f ofthe tapered roller bearing 95, in the main shaft 86.

When the tapered roller bearing 95 is assembled in the main shaft 86 ofthe large wind-power generator, the main shaft 86 is fixed to the groundvertically. First, the inner ring member 82 e is fit in the main shaft86 with the side of the large flange 88 e down. Then, the tapered roller98 is assembled in the track surface 86 e of the inner ring member 82 e.Here, since a center of gravity G of the tapered roller 98 is positionedradial inner side of the outer diameter surface of the large flange 88e, the tapered roller 98 is caught by the large flange 88 e andprevented from escaping without being tied on the track surface 86 e.Then, the inner ring intermediate element 85 is fit in the main shaft86.

According to the tapered roller bearing 95 to support the main shaft 86of the wind-power generator, a thrust load generated when the bladereceives wind, and a radial load and a moment load generated due to theown weight of the blade are applied. Thus, in order to support the loadsappropriately, an angle θ₃ formed between a rotation center ring l₃ ofthe tapered roller bearing 95, and a phantom line l₄ of the outerdiameter surface of the tapered roller 98 to be in contact with thetrack surface 83 e of the outer ring 97, that is, the track surface 83 eof the outer ring 97 (referred to as the “contact angle” hereinafter) isset such that θ₃≧40°. In addition, a contact angle of the conventionalgeneral tapered roller bearing is about 10° to 35°.

Then, referring to FIG. 38, the inner ring member 82 f and the outerring 97 are assembled before assembled in the main shaft 86 (S21). Morespecifically, the inner ring member 82 f is set with the side of thelarge flange 88 e down. Then, the tapered roller 98 is assembled in thetrack surface 86 f of the inner ring member 82 f. Then, the outer ring97 is assembled in such that the track surface 83 f of the outer ring 97is appropriately in contact with the rolling surface 84 g of the taperedroller 98.

Then, the inner ring member 82 f and the outer ring 97 are fixedlyconnected to each other (S22). More specifically, one end of an L-shapedfixing jig 92 and a bolt hole 89 f of the inner ring member 82 f arefixed by the bolt 93, and the other end thereof and the through hole 83g of the outer ring 97 are fixed by the fixing bar 94. Thus, the taperedroller 98 is restrained between the track surfaces 86 f and 83 f andprevented from escaping.

Then, as shown in FIG. 36, the inner ring member 82 f and the outer ring97 connected fixedly are lifted (S23), and assembled in the main shaft86 with the side of the track surface 83 e of the outer ring 97 down(S24). Then, as shown in FIG. 37, the fixing jig 92 is removed afterconfirming that the track surface 83 e of the outer ring 97 isappropriately in contact with the tapered roller 98 assembled in theinner ring member 82 e.

Finally, the distance d between the track surfaces of the inner ring 96and the outer ring 97 is adjusted (S25). More specifically, a width ofthe inner ring intermediate element 85 is previously adjusted, and thedistance between the track surfaces is set to a predetermined value byapplying a precompression between the inner ring members 82 e and 82 f.More specifically, the negative clearance (D₁>d₁) is provided at the topof the crowning of each tapered roller 98.

In addition, the above assembling procedures are one example, so thatanother step may be added or the order of the steps may be exchanged. Inaddition, the fixing jig 92 may have any configuration as long as theinner ring member 82 f and the outer ring 97 can be connected and fixed.

According to the above assembling procedures, when the retainerlesstapered roller bearing 95 is assembled in the main shaft 86, the taperedroller 98 is prevented from escaping. Thus, the tapered roller bearing95 can be easily assembled in the main shaft 86.

In addition, even when the present invention is applied to other typebearings such as a self-aligning roller bearing, the effect of thepresent invention can be achieved. However, since the distance betweenthe track surfaces is easily adjusted in the tapered roller bearing asdescribed above, the present invention is suitably applied to thetapered roller bearing.

Here, the center of gravity of the tapered roller 98 is moved toward theradial inner side of the tapered roller bearing 95 as the contact angleθ₃ is increased. Therefore, the above assembling method is suitable forthe bearing having the large contact angle θ₃ such as the tapered rollerbearing 95 to support the main shaft 86 of the wind-power generator. Inaddition, as another method for moving the center of gravity of thetapered roller toward the radial inner side, the roller angle may beextremely decreased, or the outer diameter of the large flange may beextremely increased. However, in those cases, since the load capacity islowered and the rotation of the tapered roller becomes unstable, themethods are not suitable for the bearing to support the main shaft 86 ofthe wind-power generator.

Furthermore, although the bolt holes 89 e and 89 f are provided in theinner ring members 82 e and 82 f, respectively in view of generalversatility, the bolt hole 89 f may be provided only in the inner ringmember 82 f that is assembled with the side of the small flange 87 fdown in the interest of an assembling operation.

In addition, although the tapered roller is used as the roller providedin the retainer segment in the above embodiment, a cylindrical roller, aneedle roller, a bar type roller may be used instead.

Although the embodiments of the present invention have been describedwith reference to the drawings in the above, the present invention isnot limited to the above-illustrated embodiments. Various kinds ofmodifications and variations may be added to the illustrated embodimentswithin the same or equal scope of the present invention.

INDUSTRIAL APPLICABILITY

The roller bearing according to the present invention is effectivelyused in the main shaft support structure of the wind-power generatorrequiring to prevent its function from being lowered.

In addition, the retainer segment of the roller bearing for supportingthe main shaft of the wind-power generator according to the presentinvention is effectively used to prevent the function of the bearingfrom being lowered.

Furthermore, the main shaft support structure of the wind-powergenerator according to the present invention can be effectively usedwhen the function is required to be prevented from being lowered.

The invention claimed is:
 1. A retainer segment provided in a rollerbearing, for supporting a main shaft of a wind-power generator, having apocket to house a roller, and arranged so as to be continuously linedwith each other in a circumferential direction, wherein said retainersegment is formed of a resin containing a filler material, wherein thethermal linear expansion coefficient of said retainer segment is1.3×10⁻⁵/C.° to 1.7×10⁻⁵/C.°, the filler material lowering the thermallinear expansion coefficient for the retainer segment as compared to aretainer segment that is made only of said resin, wherein lowering ofthe thermal linear expansion coefficient of the retainer segment suchthat the thermal linear expansion coefficient of the retainer segmentapproximates a thermal linear expansion coefficient of a steel bearingcomponent of the roller bearing and a circumferential spacing betweenadjacent retainer segments is within a range so that a function of theroller bearing can be prevented from being lowered as a result ofpushing between adjacent retainer segments, and further wherein theretainer segment is sized for a roller bearing that supports the mainshaft of a wind power generator, the roller bearing having a pocket tohouse a roller, in the roller bearing, a plurality of retainer segmentsare continuously lined with each other in a circumferential direction ofthe roller bearing.
 2. The retainer segment of the roller bearing forsupporting the main shaft of the wind-power generator according to claim1, wherein said filler material contains carbon fiber and/or glassfiber.
 3. The retainer segment of the roller bearing for supporting themain shaft of the wind-power generator according to claim 1, whereinsaid resin comprises polyether ether ketone.
 4. The retainer segment ofthe roller bearing for supporting the main shaft of the wind-powergenerator according to claim 1, wherein a filling rate of said fillermaterial in said resin is 20% by weight to 40% by weight.
 5. A pluralityof retainer segments provided in a roller bearing, for supporting a mainshaft of a wind-power generator, having a pocket to house a roller, theplurality of retainer segments arranged so as to be continuously linedwith each other in a circumferential direction, each retainer segment ofthe plurality of retainer segments comprising the retainer segmentaccording to claim
 1. 6. The retainer segment of the roller bearing forsupporting the main shaft of the wind-power generator according to claim1, having a plurality of column parts extending along a rotation axis ofthe bearing so as to form pockets to house rollers, and a connectionparts extending in the circumferential direction so as to connect theplurality of column parts, wherein said retainer segment guides saidrollers, and one guide click having a contact part with said roller anda recess part formed on the circumferential inner side of said contactpart are provided at a side wall surface of said column part.
 7. Theretainer segment of the roller bearing for supporting the main shaft ofthe wind-power generator according to claim 6, wherein said recess partis formed by shrinkage generated when said retainer segment is molded.